Lesson video

Hello everyone, welcome back to another maths lesson with me, Mrs. Pochciol.

As always, I can't wait to learn lots of new things and hopefully have lots of fun.

So let's get started.

This lesson is called, "Compare the number of objects in two sets or the difference between two measures".

And it comes from the unit, "Calculating within 20".

By the end of this lesson, you should be able to compare the number of objects in two sets, or describe the difference between two measures.

Let's have a look at this lesson's keywords, more, fewer, less, difference.

Let's practise.

My turn, more.

Your turn.

My turn, fewer.

Your turn.

My turn, less.

Your turn.

And my turn, difference.

Your turn.

Wonderful.

Now that we've practised them, let's use them.

Let's have a look at our lesson outline.

In the first part of our learning, we're going to be comparing two numbers or measures.

And in the second part of our learning, we're going to be finding the difference between two numbers or measures.

Let's get started then with the first part, comparing two numbers or measures.

Are we ready? In this lesson we are gonna be working with Laura and Andeep.

They're gonna help us with our learning.

Are you ready, guys? Let's go.

In science, the children are exploring the minibeasts in their environment.

Laura can see 7 woodlice and Andeep can see 5 worms. Wow.

Laura and Andeep compare the number of minibeasts they saw.

There are 7 woodlice and 5 worms. Can we see them there? 7 woodlice and 5 worms. Laura says that, "There are more woodlice than worms." Do you agree? Yes.

Andeep says, "There are fewer worms than woodlice." Is he correct? Yes, he is.

So both of those facts are correct.

They each explain their thinking.

We know that 7 is more than 5, so there must be more woodlice than worms. Let's practise that.

My turn, there are more woodlice than worms. Your turn.

Well done.

Now, Andeep thought about the worms first.

He knows that 5 is less than 7 so there were fewer worms than woodlice.

Let's practise this.

My turn, there are fewer worms than woodlice.

Your turn.

Beautiful.

Well done.

Why do we say fewer and not less worms? Because we said 5 was less than 7, but why is it fewer worms? "We say fewer instead of less when we compare things that we can count." So we can count how many worms we have, so we say that there are fewer.

Well done, Andeep.

Thank you for that explanation.

When we compare two sets of objects, we can use the words more and fewer.

There are more woodlice than worms. There are fewer worms than woodlice.

The set you describe first tells you whether you should use more or fewer.

If the larger number is first, we will say that there are more because there were more woodlice.

The larger number of woodlice, so we say, more.

If a smaller number is first, so we had a smaller number of worms, we would say, fewer.

There are fewer worms than woodlice.

Use these stem sentences to compare these numbers.

We have 6 woodlice and 8 worms. Can you complete the stem sentences? There are more (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

There are fewer (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

Pause this video, have a practise of those stem sentences and come on back to see how you get on.

Welcome back, I hope you had some good talking time there.

So let's have a look.

There are more, (Mrs. Pochciol humming) let me see.

I know that 8 is a larger number than 6, so there must be more worms than woodlice.

Well done if you said this.

So that means that there are fewer woodlice than worms because woodlice has the smaller number.

There are fewer woodlice than worms. Well done to you if you said these stem sentences.

Andeep and Laura now think about what else they can compare.

All of the worms are different so we could compare them.

They each carefully pick a worm to compare.

Oh, let's have a look at those.

"We could compare how long they are." They describe what they notice.

Laura's worm is more than your worm.

"We are now comparing length.

So Laura, more, isn't correct.

We would use the word, longer." We would say that your worm is longer than Andeep's worm.

"Andeep, your worm is less than my worm." Again, do we think less is the correct word to use here? "No, we would say shorter because we are talking about length, instead of less." So what would our sentence be? Andeep's worm is shorter than Laura's worm.

Let's have a practise of those.

My turn, Laura's worm is longer than Andeep's worm.

Your turn.

And Andeep's worm is shorter than Laura's worm.

Your turn.

Well done.

So instead of using more or fewer or less, when we are talking about length, we can use the words longer and shorter.

Let's have a practise of this.

The other children decide to choose a worm and compare them.

Can you use the stem sentences to compare the worms the children have found? So you can see that we've got Andeep's worm, Laura's worm, Izzy's worm, and Jacob's worm.

So can you use the stem sentences below to create your own facts? (Mrs. Pochciol humming) Worm is longer than (Mrs. Pochciol humming) worm.

Or (Mrs. Pochciol humming) worm is shorter than (Mrs. Pochciol humming) worm.

You might want to compare your stem sentences with some other children in your class.

Pause this video, have a go at creating your own sentences, and come back once you're ready to see wow we got on.

Welcome back, I hope you enjoyed creating your sentences there and hopefully shared your sentences with some of the children.

Let's have a look at what the children came up with in the Oak class.

(Mrs. Pochciol inhaling) Izzy's worm is longer than Jacob's worm.

Let's have a look.

Let's have a check of that.

I can see that Izzy's worm, wow, that's a long worm isn't it? And Jacobs is a really tiny worm, so yes, I agree with that statement.

So well done to you if you said that.

Laura's worm is shorter than Izzy's worm.

Let's have a look.

We know Izzy's is a super long worm, so Laura's is definitely shorter than Izzy's worm.

Laura's worm is longer than Jacob's worm.

Let's have a look.

Yes, that one is correct.

And finally, Andeep's worm is shorter than Laura and Izzy's worm.

(Mrs. Pochciol gasping) Let's have a look.

It, is, yes.

Laura's is longer than Andeep's and Izzy's is longer than Andeep's, so that means that Andeep's is shorter than both of theirs.

There are lots of vocabulary that we can use when we are comparing.

What vocabulary might we use to compare these examples? So you can see there we have Alex and Sofia.

What could we say about Alex and Sofia? (Mrs. Pochciol humming) Let's have a think.

Alex is (Mrs. Pochciol humming) than Sofia.

We might say that Alex is older than Sofia, or we might say that Sofia is younger than Alex.

So you might describe someone as older or younger.

We could also compare them thinking about their height, which we would use the word taller and shorter.

So what would our sentence be then? Alex is taller than Sofia, well done.

And we could also say that Sofia is shorter than Alex.

Well done.

So we might describe somebody as older and younger, taller or shorter.

Let's have a look at another one.

(Mrs. Pochciol inhaling) What vocabulary might we use to explain the difference between our elephant and a spider? (Mrs. Pochciol humming) Let's have a think.

You might use the vocabulary, heavier and lighter.

So what would be our sentences to compare heavier and lighter? (Mrs. Pochciol humming) We might say the elephant is heavier than a spider.

And we might say that a spider is lighter than an elephant.

Well done to you if you were thinking that.

(Mrs. Pochciol exclaiming) We might use the vocabulary, bigger and smaller.

So what would our sentences be to compare the elephant and the spider using bigger and smaller than? (Mrs. Pochciol humming) The elephant is bigger than the spider, and a spider is smaller than an elephant.

Well done if you were thinking this.

(Mrs. Pochciol inhaling) Now, look what we've got here.

I can see that we've got two jugs with some liquid in.

What vocabulary might we use to compare these examples? So I can see that we have two jugs with juice in it.

In this case when we have juice, we're going to use the vocabulary, more and less.

So how could we describe the difference between jug A and jug B? Well, I can see that jug A contains more juice than jug B, doesn't it? It goes up to a higher line.

And jug B contains less juice than jug A.

So why this time have we used more and less and not fewer? We use less, not fewer, because we can't count juice.

Oh, I remember, when we use fewer we have to have countable things, okay.

So when do we use, less, and when do we use, fewer? Fewer, is used for things that we can count.

Fewer, means not as many.

So you might have fewer legs than a spider because an elephant doesn't have as many legs as the spider.

"Less, is used for things that we cannot count.

It means, not as much.

So the jug B contains less juice than jug A.

Jug B doesn't have as much juice as jug A." Thank you for that, Andeep.

I think I understand it now.

So let's have a practise of this then with Task A.

Part 1 is to use the stem sentences to compare the objects in the pictures.

So A, we have there are more (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

There are fewer (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

In B, we have there is more than (Mrs. Pochciol humming) and (Mrs. Pochciol humming), and there is less (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

Remember, we're using less because we are thinking about paint.

Paint isn't countable so we have to use less for this one.

And C, we're going to be thinking about the vocabulary that we're going to use to describe this.

The flower is (Mrs. Pochciol humming) than the grass.

The grass is (Mrs. Pochciol humming) than the flower.

And Part 2 is to explore your own environment and find your own examples to complete these stem sentences.

(Mrs. Pochciol humming) is longer than (Mrs. Pochciol humming).

There are fewer (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

There is less (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

(Mrs. Pochciol humming) is taller than (Mrs. Pochciol humming).

(Mrs. Pochciol humming) is heavier than (Mrs. Pochciol humming).

And (Mrs. Pochciol humming) is shorter than (Mrs. Pochciol humming) Have fun exploring your environment and creating these wonderful stem sentences.

Come on back once you've had a go to find all of them.

Welcome back, I hope you had so much fun exploring your environment and saying all of these stem sentences.

Did you manage to find an example for all of them? Let's have a look at Part 1 first.

Using the stem sentences, compare the objects in these pictures.

So A, there are more ladybirds than spiders.

There are fewer spiders than ladybirds, because I can see that we have 5 ladybirds and 3 spiders.

So well done if you got those.

Now, we were using more and less with these paints, weren't we? There is more blue paint than red paint.

Yes, 'cause that tin is a lot bigger than the red tin.

And there is less red paint than blue paint.

Well done if you spotted that.

Now, what vocabulary did we use to describe the difference between the flower and the grass? We can say that the flower is taller than the grass, and we can also say that the grass is shorter than the flower.

Well done to you if you completed Task 1.

Let's have a look at Task 2 then.

What did our Oak children find to complete those stem sentences? Oh, "There are fewer pens than pencils." Yes, because pens and pencils are countable, so we can use, fewer.

Well done, Laura.

(Mrs. Pochciol exclaiming) "The door is taller than me." Oh, well done Andeep.

I love that you used yourself in this comparison.

"The pencil is longer than the rubber." It is.

It's longer.

We're looking at length there, well done.

And finally, "A bus is heavier than a car." You are certainly right there, Andeep.

A bus is definitely heavier than a car, especially when it's got all of those children in it.

Well done to you if you managed to find some similar examples to Laura and Andeep.

I hope you enjoyed that task.

Let's move on then to Part 2, finding the difference between two numbers or measures.

Laura and Andeep return to their first minibeast find.

There are 7 woodlice and 5 worms. "We know that we can use more and fewer to describe the difference, but can we be more specific?" Oh, so Laura wants to be more specific.

"We could find out how many more or fewer there are." A good suggestion there, Andeep.

Shall we have a go? "Let's show the number of each minibeast in a line because that's going to help us to visualise this." (Mrs. Pochciol exclaiming) I like that, Laura.

Look at that.

"We can see that there are two more woodlice than worms." Can you see that when we line them up, there are two more woodlice there, and we've highlighted that.

There are two more woodlice than worms, so how might Andeep describe this? We might also describe this that, "There are two fewer worms than woodlice," 'cause remember, we can describe it as in more and fewer.

So we can say that there are two fewer worms than woodlice.

Let's have a practise of these.

My turn, there are two more woodlice than worms. Your turn.

There are two fewer worms than woodlice.

Your turn.

Well done.

Beautiful sentences, there.

Andeep now represents this using the cubes to check he and Laura are correct.

(Mrs. Pochciol exclaiming) "We will represent the woodlice with 7 cubes," because there were 7 woodlice, we have 7 cubes.

What do we think he's going to represent the worms with? Yes, he's going to represent the worms with 5 cubes.

Yes, we were correct.

You can see that one set has two more cubes.

Can you see? (Mrs. Pochciol exclaiming) Andeep notices something when he's lining up his cubes.

He says it looks a little bit like a bar model.

Come on then, Andeep, show us what you're thinking? (Mrs. Pochciol exclaiming) "We can see 7, the number of woodlice, as the whole because this is the larger number." Okay.

(Mrs. Pochciol exclaiming) "And we can see the five, the number of worms, the number that we are comparing as a part." Can we see how this is starting to look like a bar model? (Mrs. Pochciol exclaiming) "And this part of our bar model is going to show the difference between them." I see.

So we had 7 woodlice and 5 worms and the difference between them was 2.

So 2 then becomes the other part.

I like that Andeep, very impressive.

The difference between the number of woodlice and the number of worms is 2.

We can see that quite easily on a bar model.

So let's have a look at this then.

Find the difference between the number of woodlice and the number of worms and represent this as a bar model.

As you cannot easily line them up, you could represent the minibeasts using cubes and then represent this as a bar model.

Pause this video, have a go at creating your own bar model to find the difference and come on back once you're ready to find out how you got on.

Welcome back, I hope you enjoyed creating that bar model there just like Andeep.

Shall we see how we did it? There were 6 woodlice and 9 worms, so first, let's represent these using cubes.

We have 6 cubes and 9 cubes.

Now, if we place these next to each other, we can see the difference.

(Mrs. Pochciol exclaiming) There we go.

Can we see? There we go.

We can see that the difference between the number of woodlice and the number of worms is 3 because we have those three extra cubes on one of the sets.

Let's show this as a bar model.

The number of worms is 9.

That can be seen as our whole because that's the larger number.

The number that we're comparing it with is the number of woodlice which is 6, so that becomes a part of our bar model.

And the difference between those two numbers becomes the other part.

We know that that is 3 because we saw that with our cubes.

Now you can see that we've completed our bar model.

So we can now see that, "The difference between the number of woodlice and the number of worms is 3." Well done to you if you got that the difference was 3 and that your bar model looks a little bit like mine.

The children now use their new knowledge to compare the beans that they've been growing.

They want to find the difference between the heights of their bean plants.

"My bean shoot is taller than your bean shoot, Laura." "We can measure them so that we can actually find the difference." Laura and Andeep measure the heights of their bean plants and represent this using cubes.

Laura's bean measured 4 centimetres and Andeep's bean measured 8 centimetres.

(Mrs. Pochciol humming) So what is the difference between the heights of their bean plants? "We can see that there are 4 more cubes in this set, so our beans have a difference of 4 centimetres." "Let's show this as a bar model." So first, we're going to represent Laura's bean of 4 centimetres.

Then we're going to represent Andeep's bean of 8 centimetres.

Then the other part of our bar model will represent the difference between Laura and Andeep's bean.

Let's have a look, 4 centimetres because we had those four extra cubes.

Well done, look at that bar model.

Now we can see Laura's bean, Andeep's bean, and the difference between them.

The children talk about what they have found out.

"Andeep's bean is taller than my bean.

The difference between the height of my bean and his bean is 4 centimetres." It is.

Well done, Laura.

"Laura's bean is shorter than my bean.

The difference between the height of my bean and her bean is 4 centimetres." So remember, we can describe this as the difference to how much taller or how much shorter those beans are.

Laura now explores another way that they could represent the difference between the two measures.

"We could also show the difference using a number line." (Mrs. Pochciol humming) Come on then, Laura, show us what you're thinking? (Mrs. Pochciol exclaiming) There's our number line.

First, we're going to show each measure on the number line.

Andeep's bean was 8 centimetres, so she circled 8, and Laura's bean was 4 centimetres, so she circles 4.

Now we can find the difference between them.

1, 2, 3, 4.

(Mrs. Pochciol inhaling) The difference between 4 and 8 is 4.

We can clearly see that on our number line.

"In this problem, we are looking at centimetres.

So the difference between the two measures of 8 centimetres and 4 centimetres is 4 centimetres." Wow, you can really see that quite clearly on a number line, can't you Laura? Thank you for showing us that.

So let's have a go at this then.

The tallest bean at the moment are Izzy and Andeep's beans.

So Izzy's is 10 centimetres and Andeep's is 8 centimetres.

Use the number line to compare the two measurements.

Complete this stem sentence to explain what you find.

(Mrs. Pochciol humming) bean is (Mrs. Pochciol humming) than (Mrs. Pochciol humming) bean.

The difference between the height is (Mrs. Pochciol humming) centimetres.

Pause this video, use the number line and create your own stem sentence to explain what you find between the two measurements.

See you soon.

Welcome back.

So let's see how we got on then.

We know that Andeep's is 8 centimetres tall, so let's start with the height of Andeep's bean on our number line.

We know that Izzy's bean is 10 centimetres, so let's put that on our number line.

We can see that the difference on the number line is 2.

We can see that the difference between 8 and 10 is 2.

So we can now say that Izzy's bean is taller than Andeep's bean.

The difference between the heights is 2 centimetres.

We can also say that Andeep's bean is shorter than Izzy's bean, and the difference between the heights is 2 centimetres.

Well done to you if you completed that task.

Let's get on then with Task B.

Task B, Part 1 is to calculate the difference between the numbers shown.

So A and B is using our cube representation.

So A, can you find the difference? And B, can you complete the statement and find the difference? C and D is then using our number line representation.

You'll see that C, part of the number line has been completed for you.

And D, you can create your own to show the difference between two numbers.

Part 2 is to complete the bar model and find the difference between the number of items so that you can complete the stem sentence.

So once you've completed your bar models for A and B, can you then complete the stem sentence to explain what you found? And Part 3, we know that the difference between the height of two bean plants is 3 centimetres.

One bean is 5 centimetres tall.

We can see that there.

So how tall could the other one be? A little bit of an exploring task for you there.

Pause this video and once you've had a go at Part 1, Part 2 and Part 3, come on back to see how you got on.

Welcome back.

I hope you enjoyed those three tasks there.

Let's have a look at task 1.

Task 1 was to calculate the difference between the numbers shown.

So, we can see here that we've got 5 and 4 and I can quite clearly see that there is one more cube in one set than the other.

So I can see that the difference between 5 and 4 must be 1.

Well done if you got that one.

Let's move on to B then.

We can see that the difference we are looking at is between 9 and 4.

I can see that one set has 5 more cubes than the other.

So the difference between 9 and 4 must be 5.

Well done to you if you've got that one correct.

Let's move on to the number lines then.

"We can see that we are looking at the difference between 2 and 5 because they're the two numbers that have been circled.

"So the difference between 2 and 5, we can see, is 3, because there are three steps between them on the number line." Well done if you spotted that.

And finally, you could do any number.

So Andeep, what did you choose to do for D? (Mrs. Pochciol exclaiming) We could have chosen 2 and 9 like Andeep.

Let's have a look then, Andeep, what is the difference between 2 and 9? We can see that the difference between 2 and 9 is 7.

Well done if you manage to create your own.

Let's move on to Part 2 then.

Let's complete these bar models to find the difference.

So we can see that we have 3 spiders and 5 ladybirds, so that's information we can put in.

So how are we going to work out what the difference is? "Without using the objects, we knew that the difference must be 2 because 2 and 3 combine to make 5." Well done, Andeep.

I love how you used your known facts there rather than the pictures.

There are fewer spiders than ladybirds.

The difference between the number of spiders and the number of ladybirds is 2.

Or, you might've said there are more ladybirds than spiders.

The difference between the number of ladybirds and the number of spiders is 2.

Well done if you found the difference and well done if you completed the stem sentence.

Let's have a look at B then.

We can see that we've got 8 pencils and 5 pens, and we can see that there are 3 more pencils.

5 and 3 are equal to 8, so we could've used Andeep's method there rather than using the picture.

There are more pencils than pens.

The difference between the number of pencils and the number of pens is 3.

Or you might have said, there are fewer pens than pencils.

The difference between the number of pens and the number of pencils is 3.

Well done to you if you completed Task 2.

Now, task 3 then.

Let's have a look.

We know that the difference between the height of the two beans is 3.

One bean is 5 centimetres tall.

How tall could the other one be? We can see that there could've been two different answers, so well done to you if you managed to find both of them.

The other bean could be 2 centimetres tall because that would be 3 centimetres less.

So remember, when we have the difference, it could be more or less.

So if it was 3 centimetres taller, then it would've been 8 centimetres.

So you might have found 2 centimetres as your answer.

You might've found 8 centimetres as your answer.

And welcome to you if you found both of them, I'm very impressed.

Let's have a look then at what we've been learning today.

We can compare two sets of items. There are more (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

There are fewer (Mrs. Pochciol humming) than (Mrs. Pochciol humming).

We can use a range of vocabulary to compare two measures, longer and shorter, taller and shorter, older and younger, heavier and lighter, more and fewer.

We can see the difference between two numbers or measures as the gap between them.

Cubes, bar models and number lines can help us to visualise this gap.

Well done for all of your hard work today.

I hope you've enjoyed exploring the difference between two objects or two measures, and I hope you've enjoyed getting talking in your maths today.

A final well done for all of your hard work.

Thank you for joining me today and I can't wait to continue our maths learning again soon.

Goodbye.